Technology and science reduce fertiliser reliance

Spreading effluent in autumn and winter, and the choice of crop or pasture to maximise production, can all make a difference to reducing fertiliser inputs.

Making decisions now for spring planting can reduce reliance on fertiliser inputs.

Using the milk price step-up to purchase grain to supplement feed intake may also be an economic option for some farmers.

Paul Roderick, Queensland dairy farmer and chair of the Dairy Australia board, said feedbase decisions could be supported by the recent step-up in the milk price, shared across industry by many milk processors.

“Dairy farmers are locking in prices and securing contracts for supply of fertiliser,” Paul said.

“We have secured the urea supply chain at the moment.

“For most regions, growing grass is still the most effective dairy farming option for feeding cows, but it’s expected to be at a reduced profit.”

The step-up milk price has been retrospectively applied to the financial year’s production by milk processors, providing an unexpected windfall to dairy farmers.

Paul Cocksedge is one dairy farmer who has used the step-up to purchase feed. He leases a farm near Meeniyan, in southeast Victoria, and is landlocked for extending grazing options.

“In the last couple of years, I’ve concentrated on increasing shoulder-season grazing so I can maximise pasture year-round,” Paul said.

“The milk price change means I’m now using grain to increase feed intake.

“I feed 3kg/cow in spring. Increasing the amount of grain I feed the cows will make the grazing rotation easier for me.”

Paul said mild winters in his district enabled him to regularly harvest fodder.

“About 20 per cent of the farm is harvested weekly,” he said.

“I’ll let a paddock go a bit longer to catch the zoom phase in the silage regrowth paddock, using fertiliser to push growth.”

Trevor Dennis is a retired company CEO and a 30-year veteran in the fertiliser industry, and has delivered lectures on plant growth and fertiliser inputs at Dookie Agricultural College.

He told Dairy News Australia that the short-term and expected medium-term shortfall in fertiliser imports was complex.

More than half of the world’s nitrogen is produced in the Middle East and up to 75 per cent of Australia’s urea imports come from the Arabian Gulf. Access is being affected by the war between America and Iran.

A 40 per cent tariff imposed by the Australian government since 2022 on imports from Russia, prohibits most Australian companies from sourcing nitrogen from that country.

“Also, the global shipping trade has slowed down. Ship owners have ordered their crews to go slower along their supply routes to conserve fuel, and that extra time and cost is adding to the price of fertiliser,” Trevor said.

“Scarcity and cost means that effectively the world’s nitrogen price has risen by up to 50 per cent.”

Closer to Australia, Asian governments are prioritising fertiliser access for their own population’s food production, rather than exporting to their neighbours.

“Australia’s own fertiliser production has dropped from nine superphosphate processing factories to one – and that one is in Tasmania, not on the mainland,” Trevor said.

“The dairy industry is reliant on importing DAP, MAP and sulphate of ammonia fertilisers, and that supply is not available in the same quantity.”

Trevor said it was important for dairy farmers to plan ahead.

“Good dairy farmers know their input needs and can place forward orders based on their relationships with suppliers,” he said.

“That’s the same for fertiliser, fuel and other feed sources like hay and grain.”

He also recommends applying fertiliser at the right time and in the right amount.

“The application of urea from now until the end of August is the cheapest way to grow feed,” Trevor said.

“Fertiliser use efficiency means applying fertiliser at the right time in the right amount.

“Every 1kg of dry matter grown on farm is cheaper than buying feed.

“Use the Ellinbank pasture data in your decision making.

“Use urate inhibitors to stop urea being lost to factors like denitrification.”

Dairy Australia’s Soils and Water Lead, Cath Lescun, said soil testing would help farmers identify the paddocks that would benefit from applying nitrogen fertiliser to have the best impact.

“Get your local agronomist to help you identify the best paddocks and send your tests to accredited laboratories for analysis,” Cath said.

“That knowledge will allow you to put your nitrogen on at the right place, at the right time and using the right product.”

Peter Notman runs Walcha Dairy and Notman Seeds

He said combining nitrogen application with other options would also drive pasture growth.

“Using gibberellic acid is still a good return on investment,” Peter said.

“Nitrogen applications should be strategically placed, followed up with gibberellic ccid, to enhance plant growth.

“Farmers can also use an amino acid to improve growth where they have green feed.”

Peter said Notman Seeds and Ellinbank SmartFarm had some plant plot trial results online that dairy farmers can access.

Growing crops like maize can also lower fertiliser inputs in some soil types where the plant roots are able to grow deeply and pull nutrients from the subsoil to improve growth and yield.

Jim Colquhoun, an agronomist with Nutrien Ag Solutions, said dairy farmers can reduce fertiliser inputs by identifying what crops optimise nutrient use in their soil type.

“Maize roots are three-quarters of the height of the crop,” he said.

“That means a 1.2 metre high maize crop has roots one metre below the surface.

“Turnip roots descend 750-800mm and as part of a soil amelioration process can be cultivated in a dry paddock.

“Ryegrass roots descend less than 300mm below the soil surface.”

Jim advises knowing first what your farm’s soil test are indicating before deciding on what to sow.

“Use the technology that’s available for your decision making,” he said.